Knockdown carpenter square



l Oct. 27, 1942. E. N. HANNUM KNOCK-DOWN CARPENTER SQUARE Filed oct.31,- i941 NNW@ ATTVS 1 Patented Oct. 27, 1942 UNITED STATS PTET y OFFICEKNoGKDoWN CARPENTER SQUARE Elmer N. Hannum, Sacramento, Calif. yAppucation october 31, 1941, seri-a1 No. 417,287 Y 2 claims. (c1.3'3-114) This invention relates in general to an improved carpentersrafter square, and in particular is directed to a rafter square of theknockdown type. Rafter squares of the knockdown type which are nowavailable include a blade and a tongue mounted in separable relation atadjacent ends and as a result when separated neither part has anyutility.

It is the principal object of the instant invention to provide a raftersquare of the knockdown type which comprises a blade and a tongueintegrally connected at adjacent ends; the blade being sectional and theportion of the blade which remains with ,the tongue being ofpredetermined relatively short length so that the tongue and remainingsection of the blade are usable as a square under certain circumstances,as will hereinafter appear.

A further object of the invention is to provide a rafter square whichincludes a blade and a tongue integrally connected at adjacent ends, theblade being sectional and including a unique means connecting saidsections.

A further object of the invention is to produce a simple and inexpensivedevice and yet one which will be exceedingly effective for the purposefor which it is designed.

These objects I accomplish by means of such structure and relativearrangement of parts as will fully appear by a perusal of the followingspecification and claims.

In the drawing similar characters of reference indicate correspondingparts in the several views:

Figure 1 is a plan view of the improved rafter square with the bladesections connected.

Figure 2 is a fragmentary plan view partly broken away showing thesections of the blade separated.

Figure 3 is an enlarged cross section on line 3-3 of Fig. 1.

Figure 4 is a fragmentary edge elevation of the separable section of theblade.

Referring now more particularly to the characters of reference on thedrawing, my improved rafter square comprises, as is usual, a relativelylong blade l and a somewhat shorter tongue 2 connected integrally atadjacent ends as at 3. The blade is provided as is usual withgraduations 4 on the face thereof.

The blade l of the square is sectional and includes a relatively longsection 5 and a relatively short section 6 which remains integral withthe tongue 2, the sections 5 and 6 being detachably connected togetherat adjacent ends by means which will hereinafter bedescribedindetail.` ff It will be seen that when the blade section 5 is detached from theremainder of the square the blade section B projects as a usual bladeportion from tongue 2. The length of section 6 is predetermined; thatis, it is somewhat shorter than the face width of a conventional stud orof a pair of plates, whereby when blade section 5 is detached or removedthe remainder of the device can be successfully used for work onstudding and the like which has already been erected and has sheetingetc. applied thereagainst, and for which work the full-length blade isnot suited. Also the device with the blade section 6 will be foundconvenient for many other uses.

The means detachably connecting blade sections 5 and 6 comprises thefollowing:

The blade section 5 at the end adjacent blade section 6 is formed with acentrally projecting tongue or finger 1 which is rectangular in plan,flat, and of half thickness relative to-the thickness of the blade 5.This nger 1 normally seats in a half depth groove 8 symmetrical in planto finger 1, and formed in blade section 6. A locating dowel 9 projectssubstantially centrally from the inner face of nger 1 and seats in acorresponding socket I0 in blade B at the bottom of groove 8. A pair ofrelatively short large diameter headed machine screws ll are carried inlongitudinally spaced holes l2 in the finger 1 and normally thread intotapped holes I3 in blade section 6 at the bottom of groove 8; themachine screws being substantially fiush at both ends with correspondingsurfaces of the square.

The heads of the machine screws are recessed into the finger 1, and topermanently retain the screws -in nger 1, the screw heads are here shownas being beveled or chamfered, as at I4, the finger about the screw headrecesses being headed over at certain points as at l5 to an eX- tent toprevent escape of the machine screws from the fingers 1 but withoutlimiting rotation of such screws. By reason of this heading over themachine screws remain inseparable from the blade section 5 and thus arenot subject to loss when the square is knocked down.

In order to provide a continuous and unbroken working edge for theentire blade when the sections are connected, a relatively narrowparalleledged and full-width extension 16 projects fromv blade section 5along the inner edge of blade section 6, the free end of said extensionabutting the tongue 2 and having a projecting beveled end l1 which seatsin a socket I8 in the adjacent edge of said tongue 2. The blade section6 is of reduced Width laterally in the direction of extension I6 inorder to matchingly engage said extension when the blade sections 5 and6 are connected. As is obvious, the above described square can beknocked down merely by unloosening machine screws Il from blade section6, whereupon the blade sections 5 and 6 can be drawn apart.

The projecting end I1 is tapered transversely so as to have a looseinitial t in its socket.

From the foregoing description it will be readily seen that I haveproduced such a device as substantially fulfills the objects of theinvention as set forth herein.

While this specification sets forth in detail the present and preferredconstruction of the device, still in practice such deviations from suchdetail may be resorted to as do not form a departure Vfrom the spirit ofthe invention, as defined by the appended claims.

Having thus described my invention what I on said one section inparallel but spaced relation to said linger, the extension having itsouter edge flush with the Working edge of said one section, and theextension normally engaging the corresponding edge of the other sectionfrom end to end.

2. A square as in claim 1, with a tapered projection on the outer end ofthe extension, the tongue having a socket in which said projectionremovably ts.

ELMER N. HANNUM.

